Are there cryptographers with dissenting opinions to this article, or is what the author writes about generally recognised best practice?

I ask because I remember an article a while back where this same author had very confidently got some details wrong about CloudFlare and I think the CEO or CTO or someone like that had to step in and correct him.

Are you sure you're thinking of the right author? Filippo used to work at Cloudflare so I can't imagine he got the technical details about it too wrong.

Yes, definitely. It was this comment chain on an HN post: https://news.ycombinator.com/item?id=33573477